


binomial theorem

by waspfactor



Category: Assassination Classroom
Genre: Asano Gakuhou Goes To Therapy, Established Relationship, Fluff, M/M, Meeting the Parents, Post-Canon
Language: English
Status: Completed
Published: 2020-11-25
Updated: 2020-11-25
Packaged: 2021-03-09 19:47:17
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,261
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27711565
Author URL: https://archiveofourown.org/users/waspfactor/pseuds/waspfactor
Summary: gakuhou realises he might be an over-protective father when he learns of gakushuu's boyfriend. or rather, of who gakushuu's boyfriend is.
Relationships: Asano Gakuhou & Asano Gakushuu, Asano Gakushuu/Maehara Hiroto
Comments: 19
Kudos: 86





	binomial theorem

**Author's Note:**

> i swear im not a maths student PLS dont cancel me bcos of all the maths in my fics !!!
> 
> hi wasp back to spread the good word of maesano. they are.... good boys...
> 
> gakuhou goes to therapy: pog!!!!
> 
> incredibly angsty fics vs fluffy ones  
> wasp: metronomes between the two

“Is it because I’m dating another male?” Gakushuu asks rather icily. He’s not looking at Gakuhou, content at giving his dinner daggers. Gakuhou’s a little hurt that he found out that Gakushuu’s had a boyfriend through a friend of a friend. But he doesn’t blame him for that. What he does blame him for is his choice of partner.

“Frankly, Gakushuu, I don’t care what genders or sex you prefer to date. It’s just that I’m surprised you’re dating _him._ ”

“You’d be surprised at how similar we are.”

“Not to mention, his _shocking_ track record-“

“He scored 19th overall in second semester finals! He was in the top 10 for mathematics!”

Gakuhou raises a well-trimmed eyebrow. “I was talking about his _romantic_ history,” And that shuts up Gakushuu. “Just because I was so high up in my office doesn’t mean I never heard about the rumours.”

“-technically Ren’s got him beat in that department-“

“And Sakakibara is a fine, young man. Why couldn’t you have dated him?”

“This is the hill you want to die on. Matchmaker hill?” Gakushuu asks, incredulously.

“I just-“

Gakushuu folds his arms. “What’s wrong with Hiroto? Come on, don’t hold back.”

Gakuhou chooses his next words carefully. “He’s of a lower intelligence calibre.”

Gakushuu snorts at that. “Careful, you’re sounding like a principal. I thought the whole Korosensei thing taught you otherwise?”

“He was _notorious_ for his-“

“Yeah, in _junior high._ Same place where I was a massive egomaniac and _you_ brainwashed children! People change, father. Besides, we’ve been going steady for almost a year now.”

“I’m worried he won’t provide you with enough of a challenge.”

“Football. Mathematics. Physics. Italian. Music,” Gakushuu lists, counting on his fingers. “Believe me, he provides more than enough mental stimulation.”

“He’s ginger.”

“ _I’m ginger!_ ”

Okay fine, yeah, that was a weak one on Gakuhou’s behalf but _regardless._ “What’s his plans after high school?

“I believe he’s going to get a professional scholarship for football and play in one of the European leagues.”

“Aha! I always told you those who focus exclusively on sports aren’t as academically gifted as the rest of society.”

“And those who can’t do, teach but here we are.”

A silence falls on the room.

“You have no reason to dislike him. I think you’re just being petty.” Gakushuu simply says before standing up and taking both of their empty plates to the kitchen.

That was the end of that conversation. Gakuhou, still unconvinced by the thought of _Maehara Hiroto_ dating _his son_ (the Asano Gakushuu) lets the idea simmer in his mind. He brings it up at his next therapy session.

“And how have you been doing, Gakuhou?” Kanna asks. She’s the deputy faculty head of psychology at the University of Tokyo and his therapist- she’s the best money can buy, obviously. Gakuhou had been given court-mandated therapy sessions for 12 months after the Korosensei thing came out but he’d continued going anyways. Kanna was a positive influence on his life, Gakuhou decided. Plus, she was dangerously clever and saw through Gakuhou like he was a ghost. 

“I recently found out my son has a boyfriend,” He takes a sip of the tea she prepared for him. “Please don’t misinterpret me, I am very happy that Gakushuu is happy. It’s just…”

“You don’t agree with his choice of partner,” Kanna finishes for him. “Why do you not approve?”

“I…don’t know,” He embarrassingly admits. “He’s a former student of mine so I remember the odd fact or so about him but nothing enough to make me really dislike him.”

“Does Gakushuu know of this disapproval?”

“Oh, yes of course. I made it quite clear to him my stance on it. But the reasons I gave were not substantial for him to reconsider his choice,” He pauses. “Not that I essentially want him to change his life around what _I_ want for him but. I just think there’s better options for him… Is that normal?”

Kanna laughs, long accustomed to the… unusual Asano dynamic. “Well, he is your son, I’d be concerned if you weren’t a little invested in his romantic life,” She clicks her pen. “What it sounds like to _me_ is that you don’t dislike who he’s chosen but you have someone in _your_ mind that you’d think would be a better partner for him.” 

Gakuhou can’t help the gasp he lets out and Kanna only laughs.

He informs Gakushuu of his realisation that night. “I figured out my problem with Maehara.”

That gets Gakushuu’s attention, eyes sparkling with curiosity. He’s tending to his pet bearded dragon, Ravioli; last year’s birthday present ( _Father, did you know that bearded dragons eat centipedes? Stay away from Titania and Oberon, you brat)_. “Oh?”

“I always thought you’d end up with Akabane.”

Gakushuu manages to keep a straight face for 5 seconds before a snicker escapes his lips. He lowers his pet back into its tank, a smile curling up on his lips. Then, he bursts out into a giggling fit. Happy tears stream down his face. Gakuhou stands there unamused as he watches Gakushuu try to calm down.

“A-Akabane!” He pants out, clutching his stomach. “ _Him?!”_ And then he goes into another cacophony of chuckles.

Clearly, Gakuhou missed the mark on that one, if Gakushuu’s phone call later that night (where he laughs so loud that Gakuhou can hear it from downstairs) is anything to go by.

He’s tutoring a few children on vector addition in the local library when he spots Shiota Nagisa, tutoring a girl with striking pink hair. Gakuhou keeps an eye on them and when the girl goes to leave, he decides to speak to the boy.

“Shiota. How are you doing?”

Shiota, no longer the scared boy he remembers in E Class, smiles at him. “Principal Asano. I’m doing good.”

“Just Asano is fine.” They make idle chat about Shiota’s studies- he’s the only student from his graduating year that wants to become a teacher. Gakuhou feels _very slightly_ protective of him.

Shiota is smart, however, a favourite student of Korosensei, another intelligent individual. Gakuhou knows that Shiota knows that Gakuhou has a hidden agenda here. “I wanted to ask you a question. About a former classmate.”

“Sure.”

“What can you tell me about Maehara Hiroto?”

Shiota blinks before smiling softly. He clearly knows _why_ Gakuhou’s asking then. “Maehara’s certainly an interesting character. Despite his some of his, uh, questionable traits, he’s always been a supportive friend and classmate,” Shiota begins packing up. “I don’t really know much about his relationship with Asano, unfortunately. Sorry.”

Gakuhou didn’t really expect Shiota to provide a through analysis of Gakushuu’s relationship so he lets him go on his way home.

When he gets home, sees the note Gakushuu has left on the kitchen table ( _On a date. Don’t wait up_ ), he realises what he has to do.

“I want to meet him.”

The statement stuns Gakushuu so much that he forgets to block the football from going into his goal, leaving the game at 1-3, to Gakuhou. “…What?”

“I presume you’ve met his family. It’s only right if I meet him.”

Gakushuu narrows his eyes. “And how do I know you won’t kill him when I’m not looking?”

“He was in E Class, no? He’s had assassin training. If he can’t stop a middle-aged man from killing him, then clearly the Ministry of Defence needs to revaluate their training programme.”

Gakushuu scoffs at that but doesn’t rebut back. He lets him know that Maehara will be joining them for dinner tomorrow.

“You’re scared to meet him, aren’t you.”

“I am not scared to meet a teenager.”

“Don’t even lie, old man. You’ve been tapping out SOS in morse code for the past half an hour.”

Gakuhou spends the next day, twiddling his thumbs until 6pm. At 5:59pm (not like he’s been counting the seconds or anything), there’s a curt knock on the door. Gakuhou practically _clears_ the stairs, landing awkwardly on his ankle, in order to try and reach the front door first. However, Gakushuu’s a fast-little bugger and reaches the door first. Gakuhou hobbles to kitchen, wondering why he just fucked up his ankle for nothing.

There’s a brief greeting before the door shuts. Maehara Hiroto has entered the lion’s den, albeit with an escort.

“Ah. Good to properly meet you, Principal Asano,” He grins sheepishly. “Force of habit, sorry.”

While other E Class students (like Shiota and Kayano) have drastically changed their appearances, Maehara hasn’t changed much. His hair in now shoulder length and he’s had another growth spurt, actually taller than Gakushuu now. He’s dressed in a smart, navy pinstripe suit and in his hands is a bouquet of flowers. Gakuhou can pick out the alstroemerias, sunflowers and red chrysanthemums and his eyebrow twitches. He hears Kanna’s voice ring in his head- _that’s a very thoughtful bouquet¸_ she chides _._

Gakushuu picks up the bouquet and inspects it, a smile tugging on his face. “Cute. These are cute,” He gives Maehara a quick peck on his cheek. “You’re cute.” He says before retrieving a vase from the living room.

Maehara walks over to Gakuhou extended a hand. “Maehara.” He manages out, taking the other’s hand. 

Gakushuu insisted on cooking Maehara’s favourite meal, beef gyudon. Gakuhou doesn’t know if that _is_ Maehara’s favourite meal or if he’s only cooked gyudon because it’s quick so he won’t have to leave Gakuhou and Maehara alone for too long. He suspects the latter but then Maehara’s eyes light up when he sees the bowl of rice and meat so maybe both are true.

“So, Maehara, why do you think you’re suitable to date my son.”

Gakushuu chokes on his food, spluttering. Maehara looks rather unfazed and appears to be thinking of answer. “ _Father._ This isn’t the 15th century; I don’t need your blessing.”

Ugh. Fine, maybe that was a little too forward. Gakuhou tries a different approach. “Why do you like Gakushuu.” It’s a question but it comes out like an order.

Maehara opens his mouth to speak but Gakushuu whips around fast to face him. “You don’t have to answer that,” He jabs his chopstick in his father’s direction. “Stop interrogating him or I’ll put you in a home.”

“It’s fine, I don’t mind answering,” Maehara’s all smiles. Gakuhou only then remembers that romance should be one of the areas that Maehara excels in. “Okay. Well, my very first impression of Gakushuu was that I hated him.”

Radio static fizzles in Gakuhou’s mind. “ _What._ ”

Gakushuu playfully nudges Maehara. “Shut up, no you didn’t.”

“I did! I thought you were _such_ an ass,” Gakuhou stares disbelieving at the boy. He’s seen a few fair shares of worst first impressions, but this is a new low. “Not only for what you did to Yuuma, but you seemed so high and mighty. I was convinced you and your father were robots or something.”

Gakuhou’s hand falters, one of his chopsticks falls to the table. Gakushuu has a shit eating grin on his face. “And then we graduated junior high and I kinda thought that was all I’d ever see of him. But then we played in the high school circuit’s football league and…” A slow smile appears on his face. “And everything kinda happened from there.”

“That doesn’t answer my question.”

“Well, it kinda does. Hypothetically speaking, I shouldn’t really like Gakushuu-“

“I’m hurt.”

“It’s the unfortunate truth, babe. But the fact of the matter is that, despite _everything,_ I _do_ like Gakushuu. There’s no one single thing I can narrow it down to. I just love Gakushuu as a whole.”

_Love._ Gakuhou’s eyes widen, as does Gakushuu’s. Maehara’s face freezes in place; he had clearly not meant to say that. “Uhhhh.” He trails off.

There’s a small smile on Gakushuu’s face, as he looks away bashfully. “That was cute, shut up.”

Gakuhou’s throat remains unusually tight for the rest of the dinner, as they make polite conversation about mathematics. Maehara is near enough fluent in Italian and converses to the Asano’s in it.

Maehara pulls Gakuhou aside. “Thank you for having me over,” He starts off with. “You probably think that no one’s good enough for Gakushuu but I intend to prove you wrong.”

“If you’re asking for my blessing then-“

“Nah,” A grin appears on Maehara’s face. “Only person’s approval I need is ‘Shuu’s. But you’re important to him so I figure I can’t snub you out completely. You know, I was scared out of my mind for tonight.”

Gakuhou frowns. “Why?”

“Because… you’re the scary ex-principal! I was expecting to come here and be mind controlled,” He shrugs. “But then I remembered you’re still human and that every problem has a solution.”

Gakuhou can sense Korosensei’s teaching in his words. Without saying anything, he slides out the plastic ruler he’s kept in his suit jacket sleeve and aims to hit Maehara with it, who easily blocks it. He laughs.

“Gakushuu told me you would pull something like this, but I didn’t think he was serious. Better luck next time, teach.”

Maehara leaves, a smile on as his face as he spins his car keys around on his finger. Gakushuu stands outside the front door and doesn’t come back in until Maehara’s car is completely out of sight.

The next time he sees Kanna, she asks about how dinner went.

“Oh. I tried to assassinate him with a ruler.”

“Hm. Did you succeed?”

“No.”

“Maybe that’s for the best.”

Next time Maehara comes over for dinner, Gakuhou tries again and fails.

Maehara only laughs.

**Author's Note:**

> gakushuu: father stop trying to kill my boyfriend with a ruler >:(  
> gakuhou: no <3
> 
> gakushuu, with maehara: father meet my red headed, scumbag, ikeman boyfriend from e class who's fav subject is mathematics  
> gakuhou, with #karushuu written on his shirt: there has been a misunderstanding 
> 
> lmk if u enjoyed!!! stay safe, drink water n thanks for reading my fav rarepair


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